I have a 2005 Chevy Avalanche Z71 4x4 that is experiencing the following issues.


They all appeared around the same time, and are intermittent in nature.


I have replaced the Battery, Checked my fuses, had my alternator tested at several different locations, and checked several grounds. Voltage meter is not showing any excess draw, and barely moves from ~14 when these conditions occur.


I think it is the Body Control Module, can anyone give me some input on this please?


LIGHTS
Most of the time upon starting my headlights, dome lights, reading lights (if on), and gauge cluster lights flicker. (Dim and brighten) Sometimes they flicker on idle after start some times they flicker when I increase the RPMs sometimes both. Sometimes this flickering stops when I have driven for five minutes, some times the flickering persists for fifteen to twenty minutes. Generally the dome lights and headlights always flicker at the same time, and sometimes the gauge cluster lights flicker in time with everything else. This appears to have no direct correlation to ambient temperature, or vehicle temperature.

The flickering does increase in severity and flickers per minute with increased RPMS



SEAT WARMERS
Some times the seat warmers will turn themselves off at random. Both sides will shutoff at the same time.


C.D. PLAYER
The C.D. Player randomly throws me CD errors on known to be function CDs It will return to the radio, but not eject the C.D. If I return the player to C.D. Mode it will function just fine over the allegedly bad spot until the next revolt.


CRUISE CONTROL
The cruise control stopped working about a year ago, it may be unrelated. I still miss it though.


SEAT POSITION MEMORY
When I changed my battery out the seat position memory was lost, I gave it some new settings, then a week later the seat positions reverted to my original settings.


AC/HEAT
From time to time my heating system will switch its self to full bore defrost, with the temp at 90, blower at full power, and control set to automatic. This only seems to happen when I have the unit set to defrost with a blower rate of 1 bar.


This is everything I have noticed so far, If I observe anything else I will edit this post to reflect the changes.


Any help would be greatly appreciated. I am starting to get very frustrated with this OBD 2 system and am on the verge of going back to a late 80s early 90s OBD 1 vehicle. The minimal increase in gas mileage (+2-3 MPG) is not worth all the headaches this vehicle has caused me.

 

For your cruise control check the brake light sensor switch on the brake pedal. It is what caused my cruise to quit working. It is an $8 part on rockauto.com and takes about 20 minutes to change. You can look on youtube for a video of how to change it. Changed mine and have had no further problems with cruise control

 

some auto temp systems will slow the blower speed to low when the coolant is cold and the temp setting is set to hot. the system is designed to not blow cold air if hot air is requested. when the coolant temp comes up to operating temp....the automode will now increase the blower motor speed.
maybe the owners manual will have info about the auto mode?









the vehicle has diagnostics on every system. check for codes in the memory seat modules for the heater and memory problems.

check for powertrain and body codes for the flickering issue and cruise problems.